Chap6:1 o2 transport CP A&P Flashcards
(48 cards)
polycythemia
an increase in the number of erythrocytes in the blood caused by chronic hypoxemia secondary to pulmonary disease, heart disease, or prolonged exposure to high altitudes, or it ma be idiopathic (coming from an unknown cause)
pulse oximeter
a device that measures the amount of saturated hemoglobin in the tissue capillaries by transmitting a beam of light through the tissue to a receiver. this noninvasive method of measuring the saturated hemoglobin is a useful screening tool for determining basic respiratory function. this clip like device may be used on either the earlobe or the fingertip. as the amount of saturated hemoglobin alters the wavelengths of the transmitted light, analysis of the received light is translated into a percentage of oxygen saturation of the blood
bohr effect
as the PCO2 level increases (increased H+ concentration), the oxyhemoglobin saturation decreases, shifting the oxyhemoglobin dissociation curve to the right, whereas decreasing PCO2 levels (decreased H+ concentration) shift the curve to the left. the effect of PCO2 and pH on the oxyhemoglobin curve is known as the Bohr effect
carboxyhemoglobin
a compound produced by the exposure of hemoglobin to carbon monoxide. carbon monoxide from the environment is inhaled into the lungs, absorbed through the alveoli, and bound to hemoglobin in the blood, blocking the sites for oxygen transport. oxygen levels decrease, and hypoxia and anoxia may result
anoxia
hypoxia that may cause permanent damage
hypoxia
deficiency of o2 reaching he tissues of the body
hypoxemia
low blood 02
capillary shunt
a capillary shunt exists when blood flows from the right side of the heart to the left side without coming in contact with ventilated alveoli for gas exchange. capillary shunting is commonly caused by;
- alveolar collapse or atelectasis
- alveolar fluid accumulation
- alveolar consolidation
chloride shift
during carbon dioxide transport as HCO3- moves out of the red blood cells, and the Cl- (which has been liberated from the NaCl compound) moved into the red blood to maintain electric neutrality. This movement is known as the chloride shift or the hamburger phenomenon
Hamburger phenomenon
during carbon dioxide transport as HCO3- moves out of the red blood cells, and the Cl- (which has been liberated from the NaCl compound) moved into the red blood to maintain electric neutrality. This movement is known as the chloride shift
arterial-venous oxygen content difference
the difference between the oxygen content of the arterial blood (Ca02) and oxygen content of venous blood (CV02)
absolute shunt
the sum of the anatomic and capillary shunts is referred to as true or absolute shunt. absolute shunting is refractory to oxygen therapy
anatomic shunt
an anatomic shunt (also called true shunt) exists when blood flows from the right side of the heart to the left side without coming in contact with an alveolus for gas exchange. in the healthy lung, three is a normal anatomic shunt of abut 3% of the cardiac output. this normal shunting is caused by non oxygenated blood completely bypassing the alveoli and entering;
-the pulmonary vascular system by means of bronchial venous drainage
-the left atrium by way of the thebesian veins.
common abnormalities that cause anatomic shunting include congenital heart disease intrapulmonary fistula, and vascular lung tumors
blood doping
the administration of blood, red blood cells, or related blood products to an athlete to enhance performance, often preceded by the withdrawal of blood so that training continues in a blood-depleted state.
blood
the liquid pumped by the heart through all the arteries, veins, and capillaries, the blood is composed of a clear yellow fluid, called plasma, and the formed elements, and a series of cells with different functions. the major function of the blood is to transport oxygen and nutrients to the cells and to remove carbon dioxide and other waste products from cells for detoxification and elimination. adults normally have a total blood volume of 7% to 8% of body weight, or 70/ml/kg of body weight for men and about 65 ml/kg for women. blood is pumped through the body at a speed of about 30 cm/sec, with a complete circulation time of 20 sec
HCO3-
(bicarbonate) an anion of carbonic acid in which only one of the hydrogen atoms has been removed, as in sodium bicarbonate (NaHCO3)
DO2
(Total oxygen delivery) the total amount of oxygen delivered to transported to the peripheral tissues
VO2
(oxygen consumption) the amount of oxygen in milliliters per minute that the body requires for normal aerobic metabolism; normally about 250 ml/min
O2ER
(oxygen extraction ration) the amount of oxygen extracted by the peripheral tissues divided by the amount of oxygen delivered to the peripheral cells. normally, about 25%. also known as oxygen coefficient ration or oxygen utilization ration.
pulmonary shunting
that portion of the cardiac output that enters the left side of the heart without exchanging gases with alveolar gases
relative shunt
pulmonary capillary perfusion in excess of alveolar ventilation; commonly seen in patients with chronic obstructive lung disorders and alveolar-capillary diffusion defects. also called a shunt like effect
shunt like effect
pulmonary capillary perfusion in excess of alveolar ventilation; commonly seen in patients with chronic obstructive lung disorders and alveolar-capillary diffusion defects. also called relative shunt
venous admixture
the mixing of shunted, non-deoxygenated blood with deoxygenated blood distal to the alveoli
hypoventilation
an abnormal condition of the respiratory system that occurs when the volume of air that enters the alveoli and takes part in gas exchange is not adequate for the body’s metabolic needs. it is characterized by cyanosis, polycythemia, increased PaCO2 and generalized decreased respiratory function. Hypoventilation may be caused by an uneven distribution of inspired air (as in bronchitis), obesity, neuromuscular or skeletal disease affecting the thorax, decreased response of the respiratory center to carbon dioxide, or a reduced amount of functional lung tissue, as in atelectasis, emphysema and pleural effusion. the results of hypoventilation are hypoxia, hypercapnia, pulmonary hypertension with cor pulmonale, and respiratory acidosis. treatment includes weight reduction in cases of obesity, artificial respiration, and possibly tracheostomy
